Mar 12, 2012

Capturing wild yeast

I've been really keen to try and capture some wild yeast to use in a brew since I read about it in a homebrew forum a couple of years ago. It's a romantic idea, capturing the essence of Tasmania in a beer and creating something truly unique. A Tasmanian Lambic.

The main characters at work in a sour beer are the yeasts saccharomyces and brettanomyces, and the bacteria lactobacillus and pediococcus. These are pretty much everywhere so the plan is to capture some of these wild bugs from around my place and see what kind of character they give a beer. I used 4 jars to maximise the chance of success. If more than one works out then I'll mix them together and see what happens.

I cooked up 500ml of water with 50g of dried malt extract and divided it 4 ways. I covered the jars that are going outside with some cloth to keep any marauding insects and other debris out of the starters.

Jar 1 has a few grapes from our vine. Hard to see them but they're in there.

Jar 2 on the deck

Jar 3 on the disintegrating seat

Jar 4 under a very late fruiting peach tree

I've left jars 2-4 outside overnight and I'll collect them tomorrow morning. Jar 1 is on top of the fridge and hopefully some brettanomyces yeast from the grapes is already going to town on the grape/wort stew.

It's a longish term project. These starters might be duds and even if they're all good, I don't expect to have a finished beer in less than 8 months and possibly quite a bit longer. I'll brew a simple recipe and seeing how the bugs go with it. If it turns out well, I'll save the yeast and use it again.